Crystal structures, Hirshfeld surface analysis and PIXEL calculations of four (E)-1-(2-hydroxyphenyl)-3-phenylprop-2-en-1-one derivatives, containing methoxy substituents. The importance of π interactions

Crystal structure, Hirshfeld surface analysis and Pixel calculations of the monohydrate of (E)-3-(2-hydroxy-5-methoxyphenyl)-1-(2-hydroxy-4-methoxyphenyl)prop-2-en-1-one: occurrence of π interactions

A detailed structural analysis has been carried out on the monohydrate of (E)-3-(2-hydroxy-5-methoxyphenyl)-1-(2-hydroxy-4-methoxyphenyl)prop-2-en-1-one, 1·H 2 O. The molecule, 1, shows a small deviation from planarity with an interplanar angle between the phenyl groups of 13.32(6)°. Classical O–H⋯O hydrogen bonds involving the water molecule play significant roles in determining the overall structure. The chalcone molecules in the structure are linked directly by C–H⋯O and off-set face-to-face π⋯π intermolecular interactions, as well as indirectly via interactions involving the water molecule in an elaborate spiralling hydrogen bonding scheme. The relative contributions of various intermolecular contacts were investigated using Hirshfeld surface analysis and the associated two dimensional fingerprint plots. Pairs of molecules were identified in the crystal structure using the Pixel method. The Pixel lattice energy calculations revealed that the dispersion and the Coulombic components were the major contributors to the packing stabilization. Comparisons were made between the structures of 1·H 2 O and hydroxylated (E)-3-(2-hydroxyphenyl)-1-phenyl-prop-2-en-1-one derivatives, in particular in regards to the participation of π interactions.